The present invention generally relates to object positioning for image acquisition. In particular, the present invention relates to object positioning with respect to the isocenter of an acquisition system for image acquisition.
Medical diagnostic imaging systems encompass a variety of imaging modalities, such as x-ray systems, computerized tomography (CT) systems, ultrasound systems, electron beam tomography (EBT) systems, magnetic resonance (MR) systems, and the like. Medical diagnostic imaging systems generate images of an object, such as a patient, for example, through exposure to an energy source, such as x-rays passing through a patient, for example. The generated images may be used for many purposes. For instance, internal defects in an object may be detected. Additionally, changes in internal structure or alignment may be determined. Fluid flow within an object may also be represented. Furthermore, the image may show the presence or absence of objects in an object. The information gained from medical diagnostic imaging has applications in many fields, including medicine and manufacturing.
Obtaining an imaging an object or patient using an imaging system typically involves exposing the object or patient to a certain amount of radiation, such as x-ray radiation. The more exposures or image scans executed, the greater the radiation exposure of the object or patient. Increased radiation exposure raises health concerns for a patient being imaged. Additionally, health and safety standards limit radiation dosage for a patient imaging scan. Health and safety standards may impact image quality due to reduced or lower quality image scans. Thus, a system that minimizes radiation dosage and exposure to a patient would be highly desirable.
Tomographic reconstruction reconstructs tomographic images for two-dimensional and three-dimensional image scans. Tomographic reconstruction reconstructs an image from image data projections (such as x-ray projections) generated in an image acquisition system. Data from multiple projections are combined to produce an image describing the object. Often, two-dimensional slices are reconstructed from scans of a three-dimensional object. The two-dimensional slices may be combined to construct a three-dimensional image.
During tomographic reconstruction, an object or patient organ being imaged is placed at or near a center of rotation (i.e., the isocenter) of an acquisition system being used (an x-ray source and detector, for example). For reconstruction of two-dimensional x-ray views acquired on a C-arm imaging system, for example, centering of an object or organ is usually performed under continuous two-dimensional x-ray fluoroscopy. That is, several lateral and frontal projections are taken until an optimal position has been found from the specific x-ray acquisitions. Therefore, a method of positioning an object or patient organ at or near the isocenter of an image acquisition system would be highly desirable.
Therefore, a need exists for an improved object positioning system for positioning an object at the isocenter of an acquisition system for image acquisition.